The present invention relates to building assemblies having purlin type secondary structural members supported by underlying primary structural members and tertiary structural members supported by the purlin type secondary structural members and more particularly, but not by way of limitation, to a structural bracing system and methods for stabilizing such tertiary structural members to minimize or prevent compressive stress failures. In one aspect, the present invention relates to a structural bracing system and methods for stabilizing purlin type secondary structural members and tertiary structural members to increase the load carrying capacity of the secondary and tertiary structural members by substantially restricting the translation and rotation of the secondary and tertiary structural members.
Purlins are generally relatively long Z-shaped or C-shaped members that are bolted to extend across metal roof beams that form part of the primary structure of a metal building, such building frequently referred to as a pre-engineered building. A roof assembly is constructed over the purlins and most frequently consists of layered insulation battings and roofing panels attached to the tops of the purlins.
It is well known that a metal panel roof supported by underlying purlins must transfer load to the primary building structure through the purlins. This load will be both from live loads (ambient elements of nature, repairmen, temporarily stored roofing materials, etc.) and from dead loads (permanently installed air conditioners, etc.).
It is in particular the live load conditions which alternately place building purlins in tensional and compressive stress. While attempts have been made by prior art teachings to strengthen a purlin system with bracing, none have been as totally compensatory for both purlin tensional and compressive stressing as presented by the present invention.